FLYWHEEL?

I was driving down the road and all of a sudden when I pulled up to a stop light the car was wanting to pull forward against the brakes. Then shortly afterwards I heard a loud clicking then a pop and I had no gears I idled into a parking lot, shut off my car, and then tried to start it again, but there was a loud grinding noise and it wouldn't start. I checked the tranny fluid and it was gone but the day before it was full and had no signs of discoloration and didn't smell burnt. So i'm at a loss. I've been told it's the flywheel but i'm not sure I'f you could please help I would be eternally grateful. Also do I have to pull the entire engine and tranny at the same time or will the tranny come out seperatly. Thanx.A desperate car owner.